Motor vehicles generally utilize hydraulic brake systems in which pressurized hydraulic fluid is used to transmit force necessary to engage brake shoes. Generally, various components of a brake system such as the master cylinder, actuator and brake cylinders may be interconnected by lines including reinforced rubber hoses having couplings at each end. It is current practice to utilize threaded connections for many of these couplings but it is more desirable to use quick connect couplings whenever possible. With quick connect couplings, a connection is made by simply shoving a coupling over a tubular member. It is, of course, important that the occurrence of hydraulic leaks is minimized and that the assembler know that positive hydraulic coupling has been accomplished when "quick connecting" a hose to a tube.
One area in which it is sought to replace conventional hydraulic couplings which rely on threaded connectors with quick connect couplings are the couplings in which 1/8 inch 3/16 inside diameter hydraulic brake hose is coupled to formed metal tubes which have an internal diameter of about 0.135 inch. With such small diameters, it is frequently difficult to actually know if a positive connection has been made by the assembler and it is difficult to ensure that the possibility of leaks has been minimized.